What Have You Changed Your Mind About?

The mark of a scientist is being able to change his or her mind in light of new evidence, but when the online intellectual salon edge.org chose as its annual question, “what have you changed your mind about? why?,” I confess I didn’t have very high hopes for what the biologists, physicists and other scientists who post to the site would come up with.

In my line of work, if you are looking for a scientist who can argue the merits of genetically-modified crops, the details of human evolution or any other question, it is as rare as hens’ teeth to hear that the position the scientist currently holds is not the one he or she held in the past. Members of the species Homo scientificus just don’t change their individual minds (though the community does; that’s what we call scientific revolutions, as per Thomas Kuhn. Something to do with being identified with, and having an intellectual stake in, a certain position, I guess.

So it was refreshing that of the 119 (as I write this on New Year’s Eve day) scientists weighing in on edge.org, at least half a dozen had surprisingly humble, refreshing new thoughts on long-entrenched positions. You can read the scores of answers yourself (though I do not recommend it as a hangover cure), but these are my favorites:

Psychologist Steven Pinker of Harvard will astonish anyone who has followed his work in evolutionary psychology, which argues that the human mind was shaped by the evolutionary pressures that existed during the Stone Age. Thanks to these selective forces, men are predisposed (evo pysch-ists stop short of saying “hard-wired”) to mate with as many women as possible, women are predisposed to be coy and monogamous, men are jealous of sexual infidelity and women of emotional infidelity, men are predisposed to kill their stepchildren, on and on. As Pinker wrote a decade ago in his book “How the Mind Works,” for 99 percent of human existence, “people lived as foragers in small nomadic bands. Our brains are adapted to that long-vanished way of life, not to brand-new agricultural and industrial civilizations,” and humans have essentially stopped evolving biologically.

Now, says Pinker, “though I stand by a lot of those statements, I've had to question the overall assumption that human evolution pretty much stopped by the time of the agricultural revolution.” Instead, recent genetic findings show that thousands of human genes have evolved since then. If so, then—drum roll, please—“evolutionary psychology might have to reconsider the simplifying assumption that biological evolution was pretty much over and done with 10,000-50,000 years ago.” Pinker suspects that will not lead to “radical” revisions of our understanding of human nature, which he argues is deeply similar across cultures (others, of course, disagree). But if our minds are not creatures of the Stone Age, then many of the darker aspects of human nature that evo psych has always argued are our lot might be no more so that Neanderthalian brow ridges.

A number of scientists are waving the white flag when it comes to the power of reason over superstition. One of the strongest arguments for scientific literacy has long been that if people knew a little biology, chemistry and physics, they would not be taken in by health quacks or get swindled by tarot-card readers and other pseudoscientific offerings. But as neuroscientist Marco Iacoboni [iacoboni.bmap.ucla.edu/] of UCLA admits, “Some time ago I thought that rational, enlightened thinking would eventually eradicate irrational thinking and supernatural beliefs. . . . [But 30 years later,] irrational thinking and supernatural beliefs are much stronger than they used to be, permeat[ing] ours and other societies.” He blames the fact that science has only a marginal role in public discourse (“there are no science books on the New York Times 100 Notable Books of the Year list”), partly because scientists tend to “marginalize themselves and make it difficult for science to have an impact on their society.” He suggests that this dreary picture will improve if scientists “step up and claim wisdom outside their specialty.”

Really? Molecular biologist Lee Silver of Princeton has his doubts. He once thought that "if we could just get people to understand the science, they’d agree with us, . . . [and that] “modern education would inevitably give rise to a populace that rejected the idea of a supernatural soul.” No more. He has had too many encounters with “well-educated defenders of the irrational . . . about a host of contentious biological subjects including evolution, organic farming, homeopathy, cloned animals, ‘chemicals’ in our food, and genetic engineering. Much to my chagrin, even after politics, ideology, economics, and other cultural issues have been put aside, there is often a refusal to accept scientific implications of rational argumentation.” As he sadly concludes, “irrationality and mysticism seem to be an integral part of normal human nature, even among highly educated people. No matter what scientific and technological advances are made in the future, I now doubt that supernatural beliefs will ever be eradicated from the human species.”

In a related vein, physician and social scientist Nicholas Christakis of Harvard is now questioning the supremacy of genes over culture, saying that he has changed his mind about whether “culture can change our genes.” Like Pinker, he now believes that “human evolution may proceed much faster than I had thought.” Even more intriguing, “humans themselves may be responsible.” In societies where a stable supply of milk is available, for instance, people evolve genes making them lactose-tolerant, as has occurred in just the last 3,000 to 9,000 years several times in Africa and Europe. In societies where population density is high enough to spread epidemic diseases such as typhoid, some populations evolve genes that confer resistance to the disease.

Christakis concludes, “It is hard to know where this would stop. There may be genetic variants that favor survival in cities, that favor saving for retirement, that favor consumption of alcohol, or that favor a preference for complicated social networks. There may be genetic variants (based on altruistic genes that are a part of our hominid heritage) that favor living in a democratic society, others that favor living among computers.”

One can detect a whiff of revolution in the air. Harvard biologist Marc Hauser says he has changed his mind about “Darwinian Reasoning.” No, he has not become a creationist, but is now more skeptical of the dogmatic view that all traits are adaptive. "In recent years, I have made less use of Darwin’s adaptive logic,” Hauser writes. “It is not because I think that the adaptive program has failed, or that it can’t continue to account for a wide variety of human and animal behavior. But with respect to questions of human and animal mind, and especially some of the unique products of the human mind—language, morality, music, mathematics—I have, well, changed my mind about the power of Darwinian reasoning. . . . [W]here I have lost the faith, so to speak, is in the power of the adaptive program to explain or predict particular design features of human thought. Although it is certainly reasonable to say that language, morality and music have design features that are adaptive, that would enhance reproduction and survival, evidence for such claims is sorely missing.”

For those of you with long memories of what were called the evolution wars before that term was co-opted by evolution vs. creationism battles, look up the classic 1979 paper by Stephen Jay Gould and Richard Lewontin on spandrels. It will be interesting to see if more biologists reject the strict adaptationist paradigm.

The edge.com forum is sprinkled with other nuggets of mind-changing. Read why psychologist David G. Myers of Hope College now believes that “newborns are not the blank slates I once presumed, . . . economic growth has not improved our morale, the automatic unconscious mind dwarfs the controlled conscious mind, traumatic experiences rarely get repressed, personality is unrelated to birth order, . . . opposites do not attract, [and] sexual orientation is a natural, enduring disposition (most clearly so for men), not a choice.”

Moving from biology to physics, cosmologist Paul Steinhardt of Princeton no longer believes that cosmic inflation created the structure of the universe, and now feels “compelled to seek a new explanation that may or may not incorporate inflation. . . . Quantum physics turns out to play an absolutely dominant role in shaping the inflationary universe. In fact, inflation amplifies the randomness inherent in quantum physics to produce an universe that is random and unpredictable. . . . Speaking for myself, it may have taken me longer to accept its quantum nature than it should have, but, now that facts have changed my mind, I cannot go back again. Inflation does not explain the structure of the universe.”

Edge is the brainchild of New York literary agent and “third culture” impresario John Brockman. The third culture, a term he coined, “consists of those scientists and other thinkers in the empirical world who, through their work and expository writing, are taking the place of the traditional intellectual in rendering visible the deeper meanings of our lives, redefining who and what we are.” For this year’s question, his third-culturati really came through.